Package and a method of filling thereof

ABSTRACT

A package comprising a bag of flexible sheet material which, prior to being filled, is laid flat and comprises two opposing side walls ( 2 ) substantially in contact with each other, which side walls are tightly sealed along opposing side edges ( 5 ), the bag also comprising a bottom wall ( 3 ) which is folded double and has two fields ( 31 ) facing each other received between the lower parts of the side walls ( 2 ), the parts of the end edges of the bottom wall being sealed together. At least in the vicinity of the fold line ( 32 ), the side edges of the bottom wall are joined to the side walls at their side edges and a string of springy, elastic material ( 4 ) is connected to a respective side wall ( 2 ) at its lower edge ( 21 ), along substantially the entire length of the lower edge of the side wall when the package is in its flat state, and the two material strings are separated from each other. The package is filled by inserting a substantially leaf-shaped pouring mouthpiece into the flat neck of the pack-age and introducing liquid through the mouthpiece, after which the neck of the package is sealed. The packages may be joined together in a coherent chain of packages attached to each other at their side edges.

The invention relates to a package of the type revealed in the preambleto the appended independent claim directed to a package and a chain ofsuch packages.

The invention also relates to a method of filling such a package withfluid material.

An inconvenience with known packages, particularly for liquid, is thatthey require a relatively large amount of packaging material if they areto be stable. At the same time a problem arises in that, after use, thepackages take up considerable space when being disposed of or handed infor recycling, etc.

It is known per se to package liquids in “pillow packages” of flexiblematerial. However, one drawback with pillow packages of thin, flexiblesheet material is that they have little or no stability, i.e. thepackages cannot be placed in stable orientation on a horizontal surface,but tend to fall over which constitutes a particular inconvenience oncethe package has been opened for drinking.

FR 1597215 reveals a package which, when in flat, unfilled statecomprises two opposing side walls substantially in contact with eachother, and a double-folded bottom wall received between the lower partsof the side walls, the end edges of the bottom wall being sealedtogether, and the side walls being tightly sealed together alongopposing, substantially parallel side edges. The bag in flat state maythus be considered to be formed from a lengthwise section of acontinuous strip of plastic foil folded to have a W-shaped profile, theseparated edges of the section being sealed with welding seams runningtransversely to the longitudinal direction of the continuous strip.

According to FR 1597215 the lower edge portion of each side wall hasbeen flat-welded to the adjacent edge portion of the bottom wall so thata fin is formed along the lower edge of each side wall. When the bag isfilled, these fins form a belt around the bottom of the bag. In thefilled package, when standing on a surface, the fin extends downwardlyso that its free end lies slightly above the surface and that itsconnection to the bag/package is an equivalent distance above thesurface. When the bag is filled the belt formed by the fin assumes asomewhat conical shape, which narrows towards the bottom. The attachmentof the fin to the side wall has little rigidity and the fin itself haslittle rigidity. The fin/belt is thus unable to offer any substantialresistance to prevent the bag, filled with liquid and standing on asurface, from falling over.

Admittedly such packages can be stabilized by placing them in a holderof some type that offers the desired stability but this solution has notbeen widely used in practice.

One object of the invention is therefore to provide a package formed bya bag of flexible, thin sheet material that substantially lacks anyrigidity of its own which bag, after filling with a material,particularly a fluid material and most particularly a liquid, is sealedto produce a pillow package.

The object of the invention is thus to provide a package that, althoughthe sheet material of the package substantially lacks rigidity of itsown, still gives the package when standing on a horizontal surface andfilled with fluid material, such stability that it is able to stand onits own and, although with some caution, can be lifted to permit a userto drink from it or pour through the upper generally horizontal edge ofthe opened package.

The object is thus to eliminate the inconveniences mentioned.

The object is achieved by means of the invention.

The invention is defined in the appended independent package claim.

Embodiments of the invention are revealed in the appended sub-claimsrelating to the package.

The invention also comprises a method of filling a package in accordancewith the invention with a fluid material, particularly a liquid.

The method in accordance with the invention is defined in the appendedindependent claim relating to the method.

Embodiments of the method are defined in the appended sub-claimsrelating to the method.

The object of the method is, during use of packages in accordance withthe invention, to achieve quick filling of the package with a liquidwhile producing little foam in the package prior to dosing.

The packaging blank in accordance with the invention comprises a bag offlexible material, the bag being laid flat prior to being filled withmaterial and the package bag in flat state comprising two opposing sidewalls, parallel and substantially in contact with each other, which sidewalls are tightly sealed along opposing side edges, the bag alsocomprising a bottom wall extending across the width of the wide walls,half of the bottom wall being folded up towards the inside of therelevant adjacent side wall at its lowermost part. The parts of the endedges of the bottom wall in contact with each other are tightly sealedtogether. The ends of the bottom wall are, at least in the vicinity ofthe fold line, joined to the side walls at their side edge join. Astring of springy, elastic material is connected to the outside of eachside wall at its lower edge, along substantially the entire length ofthe lower edge of the side wall. In a tested embodiment of the inventionthe wall consisted of a plastic foil with a thickness of 0.1 mm and theheight of the string was approximately 1.5 mm in the vertical directionof the bag and 0.4 mm thick. The string was attached to the outside ofthe side walls along its entire height. The string counteracted anytendency of the package to fall over. The package had substantiallycircular cross section with a diameter of 100 mm and a height of ca. 200mm.

It is important that the string is shaped so that it covers the junctionbetween the side walls of the filled bag and the bottom of the bagresting on the surface.

The string is preferably joined to the side wall in such a way that itcannot be tilted in relation to the wall.

For a package with a diameter of ca. 100 mm and a wall thickness of ca.0.1 mm, the string may have a thickness of at least 0.05 mm and a heightof at least 0.2 mm. The stability of the package increases with greaterthickness or height of the string. As mentioned earlier, the stringfunctions well for a package with a diameter of 100 mm when the wallconsists of a flexible plastic foil having a wall thickness of 0.1 mm,if the string has a height of 1.5-2 mm and a thickness of 0.4 mm, whenthe string is firmly attached to the outside of the wall so that itcannot be tilted in the vertical plane and when the string is placed sothat it is in contact with the surface on which the bag is resting, i.e.the string forms a peripheral part of the stretched bottom wall restingon a horizontal surface when the filled bag is vertically oriented. Thestring is thus joined to the wall at at least its upper and its lowerparts, and preferably over substantially its entire height.

When such a flat package is being filled with liquid it assumes acircular cross section as the folded edge of the bottom wall movesdownwards towards a plane tautened by the two strings of material. Theend edge connection of the bottom wall to the seam of the side walls, atleast in the vicinity of the original fold in the bottom wall, causes acertain forced control of the cross-sectional shape of the lower part ofthe liquid-filled package. The breadth of the package is defined by thebreadth of the bottom wall. The material strings result in stabilizationof the package. It seems that the material string assumes a generallyU-shaped curvature on a horizontal surface and thus defines a stabilizedtransition between the vertical side wall of the liquid-filled packageand its horizontal bottom and keeps this stretched. It appears,therefore, that the string prevents the side wall from sinking down andbending out to become a horizontal bottom wall.

Stabilization of the package is also obtained in the horizontaldirections that extend through the connection lines of the side walls,preventing the package from collapsing in said direction. The stringsmay possibly also be formed of a series of pieces arranged with slightspacing. However, it is preferred for the strings to be substantiallysolid and extend along the entire lower edge of the package when flat,on the lower side thereof.

In one embodiment the material strings may be applied as prefabricatedstrings that are joined to the side walls. Alternatively the strings maybe applied as a string of a non-solidified plastic material, e.g. astring co-extruded with the plastic film or a string of hot-melt glue.In other embodiments a thin, springy continuous strip of plastic filmcan be adhered to each side wall dose to and along its lower edge bymeans of conventional adhesion technology. The material string can thusbe adhered using radiation, ultrasonic, glue joint, soldering or weldingtechnology, or double-sided tape, etc.

The flat, empty package can be produced as a chain of packages, thepackages of the chain being connected to each other at the side edges ofthe side walls. The packages may thus be connected to each other bywelding seams joining the side walls and having a longitudinal tearindication in their central region, i.e. a weakening line that permitseasy separation of the packages from each other. Alternatively they mayhave a cut possibly extending up to the proximity of the upper end ofthe package.

The chain of packages is suitably made out of a continuous strip ofplastic film which is provided at the manufacturing stage with saidmaterial strings by means of extrusion or the like. Similar straightstrings may also be extruded along the side edges of the continuousplastic strip. The continuous strip is then laid flat to have aW-profile, so that the lower continuous strips are positioned as stated.The continuous strip can then be sealed with transverse seams to formthe chain and tear indications or cuts can be introduced in these seams.

The material strings at the opening edge of the packages reinforce theopening of the package and facilitate handling of the package chain andpackages. The strings may be joined to the packages at only theirlongitudinal central region. The opening edge of the packages, includingthe material strings above the neck closure of the package may bedetached after the neck is sealed, and returned to the production pointfor the continuous strip where these remnants can be reprocessed to beused in the material strings at the lower edge of the side walls of thepackages.

The re-used material usually acquires somewhat greater rigidity than theoriginal material of the film and can therefore advantageously be usedto form said material strings in the continuous strip.

The method for filling a package in accordance with the inventioncomprises orienting the package in flat state with the opening upwardsand then inserting a liquid-filling mouthpiece of considerable width(suitably 70% and preferably at least 90% of more of the length of thepackage and preferably having the same breadth as the length of the bag)and slight thickness between the side walls, parallel thereto andlowering it some way into the package, whereafter liquid is introducedthrough the mouthpiece to fill the bag. Since the bag is initiallysubstantially flat, even after insertion of the filling mouthpiece,there is initially no air volume in the package and therefore no, orvery little, foam will appear in the package when the liquid isintroduced. This is naturally providing the liquid or filling pipe doesnot contain any substantial quantity of gas. The mouthpiece isessentially formed of springy elastic material and in unloaded state hastwo normally flat walls located substantially in contact with eachother, which are flexible so that the mouthpiece is expanded by theliquid flowing through it. This means that, to a certain extent, themouthpiece is self-sealing when the flow of liquid is interrupted.

A series of such nozzles may be provided to move together with the chainor respective packages to fill the packages during transport. Themouthpieces may be arranged to move in a circular path, synchronous withthe chain/packages and can thus be inserted into or withdrawn from thepackages during their transportation. A pair of flexible clamping jawsmay clamp the neck of the bag to the mouthpiece along the length of theneck of the bag during the filling operation. The clamping jaws aresuitably flexibly pre-stressed towards each other to the closed positionand can thus clamp the neck of the bag after removal of the mouthpiece.The damping jaws may also be made as welding jaws.

When the package has been filled the neck of the bag is sealed at rightangles to the side edges, forming a sealing seam that extends betweenthe side edges of the side walls. Together with adjacent triangularparts of the package, the end parts of this sealing seam can be laidflat and folded down towards the side walls of the package or towardsthe upper end wall of the package in conventional manner. Naturally thepackage can be sealed by other sealing means.

A chain of packages can be conveyed in flat state past a fillingapparatus from which the mouthpiece is inserted into the necks of theempty bags for separate filling thereof.

The invention will be described in the following by way of example withreference to the accompanying drawings.

FIG. 1 shows a flat packaging bag in accordance with the invention,prior to filling.

FIG. 2 shows schematically a section taken along the line 11-11 in FIG.1.

FIG. 3 shows a side view of the package illustrated in FIG. 1 whenfilled with liquid, before being closed.

FIG. 4 shows schematically a view taken along the line IV-IV in FIG. 3.

FIG. 5 shows a chain of packages as in FIG. 1, on its way past aliquid-filling station and a sealing station.

FIG. 6 shows schematically a continuous strip of plastic film that canbe used as starting material for a package in accordance with FIG. 1.

FIG. 7 shows a set of wheels in a folding device for producing a blankout of a continuous strip of plastic film for a chain of packages.

FIG. 8 shows a view in perspective of a closed, filled package inaccordance with the invention.

FIG. 9 shows a blank for a bag when spread out flat.

FIG. 6 illustrates schematically a flat continuous strip 1 of thin,flexible plastic film material folded to a W-shaped profile. Thecontinuous strip comprises two side walls 2, the free edges 22 of whichare situated close together. A central part 3 of the continuous strip 1is folded in between the side walls 2 via fold lines 21 and has a foldline 32 in its mid-region. The lines 21 and 32 define the field 31.

Longitudinal sections of the continuous strip 1 are sealed by weldingtransversely to the longitudinal direction of the continuous strip,preferably perpendicular to the longitudinal direction, and are cutalong the incision. A string of springy elastic material 4 is appliedalong substantially the full breadth of the longitudinal section on thelower edge of each side 2. For the sake of clarity the string 4 is shownin the drawing spaced from the line 21 but in reality the string 4should be close to the line 21. FIG. 1 shows the welding seams 5, foldline 32 and fold line 21 when the longitudinal section 1′ is in flatstate.

This longitudinal section 1′ forms a package blank in which the portion3′ forms the bottom of the package when a fluid material, e.g. a liquid,is introduced into the upper part of the package, i.e. between the walls2 at the edges 22. The liquid poured in fills out the volume of thepackage which thus assumes a circular cross section. The fields 31 forma flat bottom surface of the package in a plane stretched out by thestrings 4. The bottom 3 and strings 4 of the filled package are intendedto rest on a flat, horizontal surface, whereupon the end portions of thefields 31 that are in connected with the side welding seams 5 initiallyfollow the seams 5 but are deflected to said plane.

The fields 31 are tightly joined together and also to the side walls 2,at least in the region of the point at which the double fold 32 isconnected to the welding seam, and preferably right down to the edges21.

The string 4 can be applied as a hot-melt string which is disposed inhot state on the edge 21 of each side wall 2. The package in flat stateillustrated in FIGS. 1 and 2 is filled by a generally leaf-shapedmouthpiece with a narrow, elongate through-flow area, being insertedfrom above between the opening edges 22 of the flat package, after whichliquid is injected through the mouthpiece 7. Since there is initially noair volume in the package 1′, there is naturally no air in the package1′ to be displaced out of the package when the liquid is introduced.Filling can therefore be performed quickly and substantially without theformation of foam. When the liquid is introduced into the package 1′ thedistance between the edges 21 increases and the fold line 32 will moveto a horizontal plane stretching between the edges 21 and the materialstrings 4 so that the fields 31 will also lie in this plane. The bottomwall 3 of the package will normally rest on a substantially flat,horizontal surface. The package 1 is therefore stable, i.e. it has notendency to fall over since the material strings 4 provide a strongstabilizing influence on the package, the bottom area of which assumesthe shape shown in FIG. 4.

The cross section of the package when filled with liquid is almostcircular, as determined by the circumference of the package, the breadthof the bottom 3 and the fact that the ends of the bottom fields 31 areconnected to the welding seams 5.

It can also be seen from FIG. 5 that the packages 1′ are formed from thecontinuous strip 1 with the aid of transverse sealing seams 50 having acentral tear indication 1, along which the packages 1′ can be separated.The chain of coherent packages 1′ can be separated before or after thepackages are filled with liquid. FIG. 5 shows that, after filling, thechain is conveyed past a pair of welding jaws 8, only one of which isshown in FIG. 5, between which the packages 1′ can be sealed with awelding seam in proximity of the upper edge 22. The filled, sealedpackages can then be separated as indicated by the line 9 in FIG. 5.

The embodiment shows the packages being produced from a continuous stripwith a cross section in accordance with FIG. 6. However, it should beclear that the blanks for the package illustrated in FIG. 1 can beformed in some other way, the starting blank naturally having a W-shapedcross section and being sealed with two parallel welding seams 5. It isnaturally also possible to establish the fields 2, 3 in the package 1′in some other manner, through connection-welding of separate sheets andapplication of the elastic strings 4 as shown on the finished package 1.

The package can be filled with fluid material such as powder, cream,liquid or the like.

If the package is given relatively large dimensions, particularly if theheight is approximately the same as the circumference, a certain cautionshould be observed when handling the package after it is opened if thevolume is 0.51 or more. A dish-shaped support device is also possible,in which the package can be placed when the contents has been drunk orpoured out.

As mentioned, the chain of packages 1′ can be manufactured starting fromthe continuous strip of plastic film. During the manufacture of thisstrip the reinforcing strings 4 can be established as continuous strings4′ that are formed when the strip of film is extruded.

As can be seen in FIG. 7 the continuous strip of film can be foldedusing conventional folding equipment, such as a pair of coaxial wheels121 between which the periphery of a third wheel 132 protrudes frombelow, and suitable guide tracks so that the plastic film is shaped to aW-profile as indicated. In this case the extruded strings 4′ must ofcourse be placed in immediate proximity of the lower periphery of thewheels 121 as shown in FIG. 7 so that they assume the position shown inthe erect package.

It is also clear from FIGS. 6 and 7 that the continuous strip of filmmay be provided with longitudinal beading 23 in the vicinity of its freeedges. The beading 23 reinforces the opening edges of the packages 1 andalso provides a support by which the packages can be suspended on andpossibly displaced along corresponding storing arrangements beforeand/or after filling. The edges of the film strip, including the beading23, can be removed when they have fulfilled their function and can thenbe returned to the production plant where the film with beading 4′ and23 are attached.

FIG. 8, finally, shows that the end portions of the transverse sealingfin 81 and the adjacent corners of the upper part of the package areflattened to form triangular corner flaps 82 that are suitably foldeddown and attached to the side walls 52 of the package, or folded up andattached to the top surface.

FIG. 9 shows a longitudinal section of a strip of plastic film fromwhich a bag can be manufactured, spread out. The strip comprises alaminate, the outer layer of which forms the inner surface of the bag,and is easy to weld, whereas the other surface layer is difficult toweld. For this reason a central recess 55 is arranged in the bottom wall3 at each end of the section. The recess 55 extends along each edge ofthe bottom wall but not all the way up to each side wall 2. The depth ofthe recess 55 from the end edge 51 of the section is less than, e.g.half the width of the welding connection zone 5. The lower part of theinner sides of the side walls 2 can therefore also be welded togetheralong the welding connection 5 in the region of the double-folded bottomwall 3; 31,31 when the bag/blank is flat, so that a durable connectionis obtained in this region at the same time as the double-folded bottomwall is welded to the side walls along the connecting seam 5. Thisincreases the strength of the weld connection between the side walls 2in the lower part of the seams 5.

1. A package comprising a bag of flexible sheet material which in itsflat state comprises two opposing side walls (2) substantially incontact with each other, which side walls are tightly sealed alongopposing side edges (5), the bag also comprising a bottom wall (3) whichis folded double and has two fields (31) facing each other receivedbetween the lower parts of the side walls (2), the parts of the endedges of the bottom wall being sealed together, the side edges of thebottom wall being, at least in the vicinity of the fold line (32),joined to the side walls at their side edges (5), characterised in thata string of material (4) is connected to each side wall (2) at its loweredge (21) when the package is in flat state, and in that the materialstring is arranged to connect with the edge of the bottom wall of thefilled package when resting on a surface.
 2. A package as claimed inclaim 1, characterised in that the material string (4) is integratedwith or applied on the sheet material, in that the two material stringsof the package are separated from each other and in that the materialstring is rigidly connected to the outside of the side wall as regardsbending in a vertical plane.
 3. A package as claimed in claim 1,characterised in that the package is formed from a lengthwise section ofa continuous strip of thin plastic film folded flat to have a W-shapedcross-sectional profile and provided with transverse welding seams (5)separated from each other.
 4. A package as claimed in claim 1,characterised in that the neck of the package is closed by means of asealing seam (81) in the longitudinal direction of the section, and inthat the end portion of the fin (81), together with adjacent corners ofthe package, is laid flat to form triangular parts that are foldedtowards and secured to an adjacent package wall.
 5. A chain of packagesas claimed in claim 1, characterised in that the packages (1′)constitute connected longitudinal sections of the continuous strip (1).6. A chain as claimed in claim 5, characterised in that eachlongitudinal section (50) connecting the packages (1′) is provided witha weakening line (51).
 7. A chain as claimed in claim 5, characterisedin that it is formed from a continuous strip of plastic film folded flatto have a W-shaped profile, and provided with material strings along thelower side edges of the packages, the continuous strip being sealed bymeans of transverse seals (5).
 8. A chain as claimed in claim 7,characterised in that the continuous strip of plastic film is providedalong its free edges with longitudinally running strings or beading (23)that hold together the packages.
 9. A method of filling a package asclaimed in claim 1 with a fluid material, particularly a liquid,characterised in that a substantially leaf-shaped mouthpiece (7) isinserted into the flat neck of the bag, parallel thereto, and in thatthe material is inserted into the bag through the mouthpiece in the flatpackage.
 10. A method as claimed in claim 9, characterised in that theopposite walls of the flat mouthpiece are made of elastomeric, flexiblematerial so that the walls substantially abut each other in the unloadedstate of the mouthpiece, and in that the walls of the mouthpiece arearranged to be elastically bent outwards due to the influence of a flowof material through the mouthpiece.